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For the impatient, here is a screenshot:


Getting an lc config going should be as easy as (on Debian):

apt install nim  #( has other options)
nimble install lc
git clone
cp -r lc/configs/cb0 $HOME/.config/lc
$HOME/.nimble/bin/lc    #-h gives a large help message

The Nim experience can sometimes have fairly rough-hewn edges, though. So far, though, something like the above has worked for me on Gentoo Linux, Debian, Android Termux, and FreeBSD.

What lc is Not

This program is not and never will be a drop-in replacement for ls at the CLI option compatibility level. ls is a poorly factored mishmash of selection, sorting, and formatting options. With fewer CLI options (but beefier configs) lc is many-fold more flexible. It can create similar output, but my main impetus to write lc was always a better functionality factoring not mere recapitulation. So, lc is not just "ls in Nim". If you want ls, it has big companies supporting it & isn't going anywhere.

lc is also not stat or find. Those have their roles for spot-checking or generating program-consumed data streams. lc is about human-friendly output, helping you see and/or create organization you want in your file sets and shine light on unexpected things as you go about everyday business listing your files. As such, absolute max performance is not a priority as human reaction time is not so fast & very large directories are usually ill-advised.

What lc is

Enough disclaimers about what lc is not. What is lc? Why do we need yet another file lister? What's the point? Well, lc

  • is clearly factored into independent actions and very configurable

  • has good CLI ergonomics (unique prefixes good enough, spellcheck, etc.)

  • supports multi-level sorting for many forward/reverse attributes

  • supports arbitrary assignment of "file kind order" for use in sorting

  • supports "multi-dimensional reasoning" about file kinds, including both text attribute layers and an "icon vector" (for utf8 "icons", anyway)

  • supports both latter-day nanosecond file times and very abbreviated ages

  • has value-dependent coloring for file times, sizes, permissions, etc.

  • can emit "hyperlink" escape codes to make entries clickable in some terminals

  • supports file/user/group/link target abbreviation via -mNum, -ma, etc.

  • supports "local tweak files" - extra config options in a local .lc (or a .lc in a shadow tree under a user's control if needed). Nice to eg, avoid NFS automounts or inversely to engage expensive classification, for dirs with special sorting or filtering needs, etc., etc.

  • supports "theming" (operationally, environment-variable-keyed cfg includes)

  • supports latter-day Linux statx/b)irth times (but works on non-Linux, too)

  • supports file(1)/libmagic deep file inspection-based classification (though using this with large directories can be woefully slow)

  • is extensible with fully user-defined file type tests & field formats

  • is compact (~1000 lines; ~300 is tables&help, ~300 of cligen/[tab, humanUt] might be part of lc if I didn't write both pkgs.)

  • has few dependencies (just cligen and the Nim stdlib)

  • is a work in progress, but a unique enough bundle of useful ideas to share. With so many features and just me as a user, there are surely many bugs.

Multi-dimensionality/Attribute Layers

The most obscure of these is likely "multi-dimensional". I mean this in the mathematical "independent coordinate" sense not a Jurassic Park (1993)-esque graphical file tree sense. Examples of dimensions may help. One file can be both an executable regular file and some kind of script source. Or both a directory and a directory with a sticky bit set. On the output side, you can also set the foreground & background colors of text independently (as well as blinking, and so on). I happen to like st for its hackability which supports bold, italic, blink, underline, struck, inverse all as 6 independent text attributes. (Color inversion involves a mapping likely too complex to be a useful visual aid.) So, 7 usable output dimensions, with 5 being shallow 1-bit dimensions. Though subjective, I find text with all these embellishments at once legible on my primary displays. Geographical map people often call this "layers". lc aids "aligning" rendering or output dimensions with classification or input dimensions.

On the input/data side there are a few natural "query" dimensions such as traits based on dtype data, stat data, ACLs, .., that performance-sensitive folk may like, but there are also many independent fields & bits just in struct stat. Not much is mutually exclusive like the dtype. So, lc users can configure however many classification dimensions to line up against their picked poisons of output dimensions. Operationally, users just pick small integer labels for dimensions/series of order-dependent tests. The first test passing within a given dimension wins that dimension. To aid debugging kind assignments you can do things like lc -f%0%1%2%3%4%5\ %f to see coordinates in the first 6 dims.


As for the bread and butter of file listing, many things that are hard-coded in other file listers are fully user-defined in lc, like a concept of dot files. Assuming you define a "dot" or "dotfile" type lc -xdot will probably exclude those from a listing. (Unique prefixes being adequate may mean a longer string if you define other file kinds with names starting with "dot".) I usually have a shell alias that does the -xdot and a related alias ending with an "a" that does not. That mimics ls usage, but without spaces and '-'s to enter. If the listing is well organized, seeing dot files by default may be considered as much a feature as a bug. Including everything by default lets "dot" be user-defined. You can also do -idot to see only the dot files (or any other user/system defined file kind) which is not something available in most file listers. It's also not always easy to replicate via shell globbing the input list. Eg., lc -r0 -idir -iodd can often be illuminating on very aged file trees.

Multi-level sorting and user format strings are similar ideas to other tools like the Linux ps, stat -c, and find -printf. Sorting by file kind is possible and "kind orders" are user-configurable. Between kind order assignment and multi-dimensionality you can filter & group almost any way that makes sense, and none of that needs any changing of lc proper - just your configuration. Less can be more with good factoring. lc is almost an "ls-Construction toolkit".

Because of all that flexibility, lc has a built in style/aliasing system. This lets you name canned queries & reports and refer to them, like lc -sl. My view is that there is no one-size-fits-all-or-even-most long-format listing. ls -sl or a shorter ll='lc -sl' alias is the way to go. Then you can make columns included (and their order, --header or not, ..) all just how you like. I usually like 5 levels of long-ness, not 2, in my personal setup.

Automatic Abbreviations

A feature I don't know of any terminal file listers using is abbreviation (GUIs have this, though and PowerShell9k/10k in single-path prompt contexts). Most everyone has probably been annoyed at one time or another by some pesky few overlong filenames in a directory messing up column widths in a file listing. lc -m16 lets you limit displayed length to 16 (or whatever) characters. lc replaces the (user-definable) "middle slice" with a user-definable string. While you can use some UTF8 ellipsis, you probably want * since that choice will make most abbreviations valid shell patterns that you can copy-paste.

Manual width & slice selection may not result in patterns that expand uniquely, but lc has you covered with a variety of automatic abbreviation options that are unique: specified head|tail, mid-point (for those 2 just leave "," fields blank), unique best-common-point (start width with "a"), unique prefix (-2) or suffix (-3), the shorter *fix (-4), the shortest 1-star-anywhere (-5) and shortest 2-star (-6). E.g.,


(or see a bigger example )

There are similar -U, -G, -M for user user names, group names, and symlink targets. While shells will not expand * in user/group names, you can change the separator to something else or even the empty string to save terminal columns as in -U4,,, and have a little grep <PASTE> /etc/passwd helper. Auto modes are not yet available for symlink targets since when they matter most they are a bit expensive (requiring minimizing patterns over whole directories for every path component).

Some Details On Other Features

In many little ways, lc tries hard to let you manage terminal real estate, targeting max information per row, while staying within an easy to visually parse table format. Features along these lines are terse 4 column octal permission codes, rounding to 3-column file ages, 4 column file sizes. If it succeeds too well you can have fewer, more spaced columns out more with lc -n4 or something. If it succeeds too poorly, you can use -m, drop format fields or identify the most effective rename targets with lc -w5 -W$((COLUMNS+10)) which shows the widest 5 files in each output column (formatted as if you had 10 more terminal cols). A hard-to-advocate-but-possible way to save space is lc -oL. Try it. { I suspect this minimizes rows within a table constraint, but the proof is too small to fit in the margin. ;-) Maybe some 2D bin packing expert can weigh in with a counter example. }

In the other direction, lc supports informational bonuses like ns-resolution file timestamps with %1..%9 extensions to the strftime format language for fractions of a second to that many places as per your discretion, rate of disk utilization (512*st_blocks/st_size = allocated/addressable file bytes), as well as newer Linux statx attributes and birth times.

lc also comes with boolean logic combiners for file kind tests, quite a few built-in tests, and is extensible for totally user-defined tests and formats. So, if there's just a thing or two missing then you can probably add it without much work. Given human reading time and fast NVMe devices, even doing "du -s" inside a format call is not unthinkable, though unlikely to be a popular default style. Hard-coding Git support seems popular these days. I do not do that yet, and I'm not sure I want the direct dependency, but you may be able to hack something together.


A post-modern, "multi-dimensional", configurable, abbreviating, extensible ls/file lister in Nim







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